Why is Good Posture Important?

Why is Good Posture Important?

Posture refers to the body’s alignment and positioning with respect to the force of gravity.  Whether we are standing, sitting or lying down, gravity exerts a force on our joints, ligaments and muscles.  Good posture involves distributing the force of gravity through our body so no one structure is overstressed, thus maintaining proper alignment and balance of the body.  Poor posture and improper alignment is most noticeable in the body’s musculature and skeletal structure.

Consider this example: an architect has to take the laws of gravity and weight distribution into account when he or she is designing a building.  And like a building with a poor foundation, a body with poor posture is less resistant to the strains and stresses we experience over the months, years and decades of life.  This is why someone with poor posture, or a poor skeletal foundation, is more susceptible to injuries, pains, and dysfunctions, and may take longer to recover as well.

When doctors or therapists look at someone’s posture, they generally first look at the alignment of the weight bearing joints in standing, for example your knees and your ankles.  Ideally from a back view the spine should have no lateral or sideways curvature and the legs should be symmetrical without undue angulation or inward/outward bending at the knees or ankles.  For example, you may have heard of someone being “bowlegged,” or of someone having “knock knees.”  These are common skeletal misalignments of the knee (figure 1).  You may have heard of “overpronation” of the ankles, or having high arches or flat feet.  These terms are used to describe postural misalignments at the ankle and foot (figure 2).  These are usually corrected by orthotics.

Figure 1 - Misalignments of the knee

Figure 2 - Misalignments of the foot and ankle

From a side view the spine should form a smooth S-shaped curve.  A plumb line is often used and dropped from the top of the head (apex), and down through the center of gravity of the body.  This same plumb line should pass through the ear lobe, the tip of the shoulder, the center of the hip joint, slightly behind the knee, and through the ankle joint (Figure 3).  With this ideal alignment the body’s weight is balanced over the spine and lower extremity joints, thus requiring minimum muscular effort to maintain yourself upright.  This alignment also evenly distributes pressure on the intervertebral discs and avoids excessive stress on the ligaments and discs of the spine.

Figure 3 - Plumb Line

The sitting position is where most of us get into trouble with poor postural habits.  This is especially true when driving or using a computer.  As we focus on the activity in front of us we tend to protrude the head and neck forward.  Because the body follows the head, the thoracic and lumbar spine tends to round forward as well.  When this occurs, the weight of the head and upper body is no longer balanced over the spinal column but instead must be supported by increased muscular energy, placing spinal ligaments on stretch (Figure 4).  Over time this leads to fatigue and eventually even pain in the neck and back.  Your shoulders may begin to look rounded forward, which can occur with computer work, driving with the seat too far back, or slouching forward for a long period of time.  Ideally then, the S-shaped curvature of the spine that is characteristic of good standing posture should be maintained in sitting as well.  This is best accomplished by sitting all the way back in a straight-backed chair and placing a folded towel or small pillow in the arch of the low back.  Fortunately, many new office chairs and car seats come with built-in lumbar supports and other adjustable featured.  This area of study is called ergonomics, and deals with optimizing posture and safety for the worker within his or her respective work environment.

Figure 4 - Sitting Posture

Sitting and standing with proper postural alignment will allow one to work more efficiently with less fatigue and strain on your body’s ligaments and muscles.  Being aware of good posture is the first step to breaking old poor postural habits and reducing stress and strain on your muscles and spine.  By putting this knowledge into practice one can prevent the structural anatomical changes that can develop if poor posture is left uncorrected for many years.